PID autotune software packages: which one?


Thread Starter

Siebe Dijkstra

We are looking for autotune software to tune mainly PLC (AB PLC5 & SLC) loops. Is it worth the cost or does one end-up tuning the loop manually? I'm aware of two companies: Rockwell RStune and Expertune. Which one should we pick or is there a 3rd package available? Thanks in advance, Siebe Dijkstra Black Belt Avery Dennison Germany
I believe that Rockwell RStune and Expertune are the same package, I have used them both and they certainly look and feel the same. They are a useful addition but I found that I needed to keep a check on some of the suggested values which whilst on paper looked ok but actually caused the loop to act worse. Alex Wilson Systems Engineer Dickinson Control Systems Ltd email: [email protected] <mailto:[email protected]> Tel: 01962 840333 Fax: 01962 842011

Heavner, Lou [FRS/AUS]

I don't mean to slight either autotune tools or those responsible for loop tuning, but in my experience, the 80/20 rule applies. About 80% of the loops benefit and can be readily tuned with almost any of the loop tuning products on the market. The rest require some thoughtful analysis in addition to or instead of the typical commercial tools. Unfortunately, it is often the 20% that are giving the plant fits or affecting operating performance. If you can afford it, take a course or at least get a book that covers analysis of process dynamics and loop tuning to supplement your autotune software. I think Greg McMillan has a well regarded book on loop tuning and I'd recommend Entech ( in Toronto for a good school on process dynamics and loop tuning. Lots of folks in the pulp and paper industry will vouch for them, but the same principles apply to all industries. Regards, Lou Heavner Emerson Performance Solutions

Dave Ferguson

Expertune is made by Gerry Engineering out of Milwaukee, WI and Rockwell Software is made in Milwaukee, are you noticing a theme here, it is the same product.........Rockwell licenses it from Gerry or at least they used to. Follow up on this before you buy it, I use Expertune and it is OK, RSTune same thing..... Dave Ferguson Blandin Paper Company UPM-Kymmene DAVCO Automation
Lou, I agree in that optimizing a loop is much more than PID tuning. This is why we recommend you go through a series of steps to optimize the loop. PID tuning being near the last of those steps:
I also suggest training from the people at TOP Control:

The reason I like these guys is that the instructors are practicing control engineers. Each TOP engineer splits his time between doing optimization work in plants or teaching people how to do it. So their instruction comes with conviction and lots of real world experience making plants run better. Although their plant optimization work can include audits of the plant, it always includes improvements along the way.

John Gerry